Here's a sweet crash-course lesson — in animated gif form — showing how the United States expanded and took shape over the course of its history.

The gif was put together by Redditor wtfjen. The map tracks a number of important turning points in U.S. expansion and contraction, from the Louisiana Purchase in 1803 to the annexation of Texas less than 45 years later to the Civil War and the rise of the Confederacy during the 1860s. The final piece of the puzzle was inserted in 1959 when Hawaii became an official state.